A specialized mass spectrometer is proposed as a universal detector for liquid chromatography applications. This device will be highly suited to the analysis of organic compounds in complex fluids and will allow biomedical researchers to rapidly identify, quantitate and even conduct structural analysis of various chemical species of interest. Operation of the instrument will require no previous training in the use of a mass spectrometer. The instrument, an atmospheric pressure chemical ionization-time of flight mass spectrometer (APCI-TOF-MS), will provide for the efficient ionization and delivery of analyte species to a mass spectrometer detector with rapid scan rate and integrating capabilities. Various chromatography conditions (flow rate, buffer concentration, solution conductivity) will have minimum impact on the performance or reliability of the instrument by virtue of a rugged atmospheric pressure inlet and ionization system. The APCI source has been specifically engineered for the delivery of the sample ions to a TCF mass spectrometer. The APCI-TOF-MS system will allow interchanging of the APCI with an Electrospray liquid introduction probe and as an integrated unit will provide consistent performance for virtually all solvents systems used in liquid chromatography separations. The Atmospheric Pressure Ion Sources can accept liquid flow rates from 0.1-2000 micromoles/min. With this range of operation the instrument is ideally suited as a capillary electrophoresis or a liquid chromatography detector. The TOF mass analyzer and integrated transient recorder will allow even the most rapidly eluting peaks to be to detected with full mass scan data while delivering high sensitivity, mass accuracy and dynamic range. PROPOSED COMMERCIAL APPLICATION: The proposed instrument will be specifically geared towards the analytical market as a general purpose chromatography or Capillary Electrophoresis detector. Its performance will be consistent over a wide range of solution chemistries and liquid flow rates and will require minimum user interaction to optimize performance. It will therefore will be a highly attractive, bench-top tool for analytical researchers with high sensitivity and/or high speed requirements.